1. Field of the Invention
The present invention relates to fixation of soft anatomical tissue to bone and, more particularly, to a drill guide for use in forming a tunnel in bone used to secure soft anatomical tissue to the bone and to a kit and method for fixating soft anatomical tissue to bone.
2. Discussion of the Related Art
Various surgical procedures require the fixation of soft anatomical tissue, such as ligaments, tendons, muscles, fascia, cartilage, connective tissue and layers of the skin, to bone. Many of the devices and techniques that have been proposed for fixating soft tissue to bone have demonstrated unreliable fixation and add considerably to the cost of surgery. Screws or anchors typically used for fixating soft tissue to bone are expensive and present the additional drawback of requiring that they either be left in place permanently or be removed subsequent to healing. Many patients are uncomfortable with the prospect of permanent implants as well as with the alternative prospect of later removal of fixation devices. Although bioabsorbable fixation devices have been proposed, such devices are considerably more expensive.
Fixating tissue to bone via a suture or wire passed through a tunnel formed in the bone has also been proposed. Illustrative instruments and methods for fixating tissue to bone using a suture or wire passed through a bone tunnel are disclosed in U.S. Pat. No. 4,672,957 to Hourahane and U.S. Pat. No. 4,744,353 to McFarland, which disclose instruments and methods for suturing soft tissue to bone, and in U.S. Pat. No. 4,622,960 to Tam, which discloses wiring a bone section to another bone section. A major disadvantage of prior procedures for suturing or wiring tissue to bone is that the suture or wire is inserted in the bone tunnel and is engaged, within the bone tunnel, by an engaging member used to draw the suture or wire entirely through the bone tunnel. Since visibility inside the bone tunnel is limited and typically obstructed, engagement of the suture or wire within the bone tunnel must be done by feel or "fishing" and is time consuming and tedious. The Hourahane and McFarland patents disclose drill guides for guiding drills to form intersecting passages in the bone defining a bone tunnel. However, there is no structural cooperation between the drill guides and the drills to limit or control the depth of insertion of the drills in the bone such that more bone than necessary is typically removed. Furthermore, the drill guide disclosed by Hourahane has pins disposed entirely within the bone during use. Accordingly, significant force must be applied to the drill guide to cause the pins to fully enter the bone, and bone must be displaced by the pins. In addition, the prior devices and methods do not recognize the significance of forming a bone tunnel to a shallow predetermined depth in bone for cooperation with a suture passer that, when introduced in an access opening of the bone tunnel, protrudes externally from the bone tunnel to engage a suture externally of the bone.
Accordingly, the need exists for a reliable and effective technique for fixating soft anatomical tissue to bone or other similar tissue without the need for permanent implants or the subsequent removal of fixation devices while being cost effective, safe for the patient and easy to execute by surgeons. A particular need exists for apparatus and a method for suturing soft tissue to bone via a suture passed through a shallow tunnel in the bone by a suture passer that engages the suture externally of the bone. The need also exists for apparatus and a method for forming a tunnel in bone to a shallow predetermined depth while minimizing the amount of bone removed and the force applied to the bone.